 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
A B737NG flight crew failed to comply with an ATC descent clearance while flying the wraps STAR to smf.
| Attributes | |
| ACN | 969406 |
| Time | |
| Date | 201109 |
| Local Time Of Day | 1201-1800 |
| Place | |
| Locale Reference | ZOA.ARTCC |
| State Reference | CA |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Make Model Name | B737 Next Generation Undifferentiated |
| Operating Under FAR Part | Part 121 |
| Flight Phase | Descent |
| Route In Use | STAR WRAPS |
| Flight Plan | IFR |
| Component | |
| Aircraft Component | FMS/FMC |
| Person 1 | |
| Function | First Officer Pilot Not Flying |
| Experience | Flight Crew Last 90 Days 200 |
| Events | |
| Anomaly | Aircraft Equipment Problem Less Severe Deviation - Altitude Undershoot Deviation - Procedural Clearance |
Narrative:
On the wraps arrival into smf; we were given a clearance to cross turlo at FL240 and then descend to FL200. While in VNAV; the pilot flying ensured the turlo waypoint had an altitude constraint of FL240 and then set in FL200 in the MCP [altitude alert window]. Upon arrival at turlo at FL240; I noticed the pilot flying was not continuing the descent to FL200. I repeated the clearance to continue the descent to FL200 at which time the pilot flying did just that. I do not know exactly how much time/distance passed after passing turlo and starting the descent.pilots must understand ahead of time that VNAV will not continue a descent after reaching an altitude constraint until it hits its next calculated descent point. If you must descend earlier; it must be done manually.
Original NASA ASRS Text
Title: A B737NG flight crew failed to comply with an ATC descent clearance while flying the WRAPS STAR to SMF.
Narrative: On the WRAPS Arrival into SMF; we were given a clearance to cross TURLO at FL240 and then descend to FL200. While in VNAV; the pilot flying ensured the TURLO Waypoint had an altitude constraint of FL240 and then set in FL200 in the MCP [ALT ALERT window]. Upon arrival at TURLO at FL240; I noticed the pilot flying was not continuing the descent to FL200. I repeated the clearance to continue the descent to FL200 at which time the pilot flying did just that. I do not know exactly how much time/distance passed after passing TURLO and starting the descent.Pilots must understand ahead of time that VNAV will not continue a descent after reaching an altitude constraint until it hits its next calculated descent point. If you must descend earlier; it must be done manually.
Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.